Cerebral embolism following contusion of the heart

Neurological sequelae of boxing

Blunt trauma to the head results in acceleration of the brain within the skull. This takes 2 forms: linear or translational acceleration which produces focal lesions, and rotational acceleration which results in 'sheering stresses' with stretching of nerves and bridging veins. Deceleration of the brain within the skull occurs when the head strikes a stationary object (e.g. floor, ring post). Cerebrovascular events are not infrequently encountered. The most common vascular sequalae is the subdural haematoma, which is also the most frequent cause of death in boxers. Epidural bleeds rare, and are generally due to deceleration of the brain. Subarachnoid bleeds have been rarely reported, but, like intraparenchymal haemorrhages, they do occur. Sudden flexion/extension of the neck is suggested as the mechanism of the occasional brainstem haemorrhage reported in boxing. Thrombosis of the internal carotid artery can occur secondary to direct blows to the neck or stretching of the contralateral carotid artery. The best known sequalae of boxing is traumatic encephalopathy--the 'punch drunk' syndrome. This is most common in second-rate and slugging type fighters. Severity correlates with the length of a boxer's career and total number of bouts, with an incidence of approximately 18%. Three stages of clinical deterioration are seen, the encephalopathy may be progressive or may remain clinically stable at any level. The first stage consists of affective disturbances with psychiatric symptoms being most marked. During the second stage an accentuation of the psychiatric symptoms occurs and signs/symptoms of Parkinsonism develop. The final stage consists of a decrease in general cognitive function together with pyramidal tract disease. Generally 2 to 3 years elapse between the first and final stages. Neuropathological studies reveal abnormalities of the septum pellucidum, scarring of the cerebellar and cerebral cortices, and loss of pyramidal neurons in the substantia nigra with neurofibrillary tangles in the absence of senile plaques. A 'groggy state' can occur in some fighters with confusion, impaired active attention and alteration of consciousness. During this period the boxer is at greater risk to suffer brain injury as defensive reflexes are frequently lost. Other neurological syndromes have been reported in addition to the 'groggy state'. These include a midbrain syndrome, headaches and cervical spinal injuries. Additionally, boxing appears to be a significant risk factor for the development of meningiomas.(ABSTRACT TRUNCATED AT 400 WORDS)

A comparative survey of the mast cells of the mammalian brain

A search for mast cells has been made in the brains of 18 mammalian species in 13 families in the orders Insectivora, Primates, Rodentia and Carnivora. In the larger animals, only the diencephalon and olfactory bulbs were examined. Mast cells were identified by virtue of their heparin-containing granules, which are stained by Alcian blue 8GX and, metachromatically, by toluidine blue 0. Within the cerebral parenchyma, mast cells were confined to the dorsal diencephalon of Erinaceus europaeus (hedgehog), Tupaia glis (tree-shrew) and Nycticebus coucang (slow loris). Some cells were next to capillaries; others were not. Mast cells were sometimes found, though rarely, in the intracerebral perivascular connective tissue leptomeninges and choroid plexuses of some of the other species examined. It is concluded that pericapillary cells (pericytes), which have been called mast cells by some investigators, are not in fact mast cells since there is no evidence for the presence of heparin. The functions of mast cells in the brain are unknown.

Retinal abnormalities in diseases of the blood

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